1. Field of the Invention
The present invention relates to method and apparatus for recording an image on a sheet of a recording medium in the both-way recording mode with the aid of a multi-ink sheet which can be repeatedly used for recording operations. More particularly, the present invention relates to method and apparatus for recording an image on sheet material which is used for electronic typewriters, facsmile apparatus, thermal printers or the like. Further, the present invention relates to method and apparatus for effectively performing recording operation on a sheet of recording medium in the both-way recording mode with the aid of a multi-ink sheet which can be used for recording operations a plurality of times and which recording operation can be performed repeatedly.
2. Related Background Art
Generally, a recording apparatus such as printer, facsmile or the like is so constructed that recording is achieved on sheet material (plain paper, plastic film, cloth or the like recording medium) by displacing a recording head in response to a printing data signal. Among conventional recording apparatuses a serial type adapted to carry out main scanning by means of the recording head is widely put in practical use.
Further, as recording process an ink jet type, a wire dot type, a thermal type or the like are well known.
Among various recording processes as mentioned above the thermal type (which is embodied in the form of a thermal recording apparatus) is so constructed that dot forming means comprising a plurality of electricity-heated converting members (heating elements) are disposed in the operative area in front of a recording head (thermal head) and recording is achieved under the effect of heating by activating the dot forming means in response to printing data signal while it is displaced along sheet material in the pressure contact state at the time of recording operation.
Further, this kind of thermal recording apparatus can comprise a heat sensitive type in which recording is effected using a heat sensitive sheet (sheet material adapted to exhibit a certain color under the effect of heating) without any necessity for an ink ribbon, and a thermal transfer type in which transfer recording is achieved using plain sheet material with the aid of an ink ribbon. Moreover, the thermal transfer type is classified into two kinds, one of them being such that a one time ink ribbon on which recording is effected only by one time on the same area is used and the other one being such that a multi-ink ribbon with which recording operation can be repeatedly performed (for instance, 10 times) is used.
To actuate a conventional recording apparatus of the type using a multi-ink ribbon (in accordance with the thermal recording process), a method of effecting one-way recording in the same manner as in the case of a one time ink ribbon while the ink ribbon is wound only in the one direction is generally employed.
However, it has been pointed out as a problem inherent to the one-way recording that it is necessary to unwind the ink ribbon by a full length at every time when it is wound by a full length and the unwinding operation takes a long time, resulting in the recording operation being achieved at a slow speed. After completion of the winding operation by a full length a ribbon cassette may be manually turned upside down by an operator. However, this means that the recording operation cannot be performed automatically.